Carburetor



Jam, 31, 1939.

D J. MACPHERSON CARBURETOR Filed Dec. 4, 1957 3 Sheets-Sheet l INVENTOR my/ma zwc zwm BY ATTORNEYS Mm. 31, 1m D. J. MACPHERSON I 9 93 CARBURETOR Filed Dec. 4, 1957 3 Sheets-Sheet '2 ATTO RN EYS I Jam 31, 193% D. J. MACPHERSON 9 -59 CARBURETOR Filed Dec. 4, 1957 3 Sheets-Sheet 5 2 Q I a ATTORNEYS Patented Jan. 31, 1939 UNlTED STATES PATENT OFFIQE CARBURETOR Duncan James Macpherson, South Lancaster, Ontario, Canada 10 Claims.

This invention relates to carburetors for internal combustion engines.

The principal object of the invention is to increase the efiiciency of the engine, and when the 5 carburetor is used on an automobile, to increase the mileage obtained from the combustion of a given quantity of gasolene.

Other objects are to preheat the air, for admixture with the gasolene before the air comes 10 into contact with the gaso-lene; to cause the air to travel through or along gasolene-saturated wicks or the like, which are partly immersed in a body of gasolene; to provide means for thoroughly mixing the vaporized gasolene and heated air 15 before the mixture is drawn into the engine; to

provide means for heating the mixture of vaporized gasolene and air, in other words, the carbureted air; to provide means for automatically changing the ratio of air to fuel when the acceler- 20 ator pedal or control has been depressed, or actuated, a selected predetermined amount; and to provide means for the escape of fumes upon backfiring occurring in the engine or other interrelated parts.

25 Several forms of the invention are more or less diagrammatically illustrated in the accompanying drawings, in which:

Figure 1 is a side elevation of an assembly of my improved carburetor with an internal com- 30 bustion engine;

Fig. 2 is a vertical section through the carburetor;

Fig. 3 is a horizontal section through the carburetor taken approximately on the line 3-3 of Fig. 2;

Fig. 4 is a vertical section through the mixing chamber taken approximately on the line 44 of Fig. 2;

Figs. 5 to 9 inclusive show details of construc- 40 tion;

Fig. 10 is a vertical section through a modified form of carburetor, and

Fig. 11 is a horizontal section taken approximately on the line ll--ll of Fig. 10.

Referring to the drawings, E indicates a typical automobile engine of which Me is the exhaust manifold, and Mi the intake manifold. The carburetor is indicated at D. To the intake manifold is connected a pipe or tube It in which is pivotally mounted a suitable butterfly throttle valve or control (not shown). Fixed to the spindle or shaft l I of the valve is a lever or crank l2 which is pivotally connected, as at l3, to the 55 accelerator rod M. The valve is operated from its normal position by the accelerator rod, all according to known practice.

The tube It is operatively connected to a pipe l5, one end of which opens into the carburetor at It, while the other end terminates in an inclined rim ll. Clamped adjacent the end ll of the pipe E is a ring l8, on the upper end of which pivots a closure l9 adapted to engage the rim ll by gravity, to thus close the end of the pipe. The closure is provided with air apertures 22. Any excess pressure within the pipe l5, such as may be caused by backfiring, will swing the closure open. Sliding in the closure l 9 is a threaded rod fit on the inner end of which is fixed a disc 2i of a diameter to extend beyond the apertures 15 22 and. thus close the same when the disc is in engagement with the inside or inner face of the closure. Between the closure and a wing nut 23, and encircling the rod 20, is a spring 25 which operates to normally retain the disc in engagement with the inside face of the closure, but upon sufficient suction being induced within the pipe it the disc moves inwardly to open the apertures 22 and admit air into the tube is from the atmosphere. The tension in the spring 24, and there- 25 fore the resistance which it offers to the inward movement of the disc, is determined by the position of the wing nut on the rod.

Mounted on the top of the carburetor D is a. valve 25. Between the lever 21 of the valve and a lever 26 pivotally mounted on a bracket B fastened to pipe i0, is a connecting rod 29, the rod being pivotally connected with the lever 28 as at 31!. The lever 28 extends below its pivotal connection 32 with the tube ill to lie in the path 35 of the accelerator rod l4 and be engaged thereby when the rod has been sufficiently depressed or moved by the accelerator pedal. The accelerator rod may thus terminate in a circular threaded portion 3 on which is adjustably mounted a nut 35. The lever 28 is so positioned relatively to the accelerator rod that the nut 35, and not the rod itself, will engage the lever. In other Words, the engagement of the nut, in eifect a shoulder, with the lever 28, will cause the latter to be swung against the action of a tensioned spring 31, to move the connecting rod 29 lengthwise (in the direction of the arrow in Figure l) to thus open the valve 26. This valve, as will be seen, is operated to admit air from the atmosphere into the carburetor, when the accelerator has reached a selected, predetermined position, or in other words, when the accelerator pedal has been depressed a selected, predetermined amount. A stop or lug 36A on the bracket 35B pivotally supporting the lever 28 determines the position of the latter under the action of the spring 31.

The carburetor proper D consists of a casing or container C, divided into a vaporizing chamber, in the bottom of which is enclosed a body of gasolene, and a mixing chamber, in which the vaporized gasolene and air are mixed. The casing C, which may be of galvanized iron, is divided, as aforesaid, into the vaporizing chamber or compartment 35A and the mixing chamber or compartment 36, these two compartments being operatively connected at the top by a passage or pipe 31A. Gasolene is admitted into the bottom of the compartment 35A by a pipe 38 from the fuel tank (not shown) a suitable float-controlled Valve 39 automatically operating to maintain the level of the gasolene in the bottom of the compartment 35A at a certain level. Air is admitted into the vaporizing chamber, above the level of the gasolene, by a pipe Ml, the intake end of this pipe being formed with a sleeve 4! encircling a portion of the exhaust manifold, so that the air admitted into the vaporizing chamber is preheated by its passage along the manifold. The casing may conveniently provide inner side walls spaced from the outer side walls to form passages 8|; apertures 86 in both the inner walls and the side walls of a tubular member 43, to be described, serve to allow air to enter into the tubular member, all as best shown in Figure 3.

Within the vaporizing chamber, and extending substantially over its entire width, is a metal tubular member 43 of rectangular cross-section, within which is placed a wick W consisting of a strip of felt or the like wrapped upon itself, as best shown in Figure 2. A metal form 64, as best shown in Figure 2, is used to form a support for portions of the wick. Thus, the form may comprise two spaced, curved members or plates 5 and 46, having therebetween a straight or flat Wall or member 41. The wick strip is passed over and below the curved members 55 and 5, being wrapped upon or over itself to form a plurality of superposed or adjacent layers or thicknesses. Thin spacers 5B, of metal or stiff felt, are disposed between adjacent layers of the wick, and the bars and layers secured to the adjacent wall or tubular member 63, as by bolts 39, or secured to the wall t? of the form 46, as the case may be, in zig zag formation, the purpose being to substantially close the passage constituted by the tubular member 43 at a plurality of spaced points, while increasing the effective surface of the wick. By the use of the thin bars 58 and bolts 39, the tension in the wick may be to some extent adjusted. Preferably, as shown, the upper layers or portions of the wick may be in part supported by a pipe 52 operatively connected to the float valve 39 as by a pipe 56. This pipe is perforated at a plurality of spaced points, so that gasolene will be led to this pipe to drop onto the underlying portion or portions of the wick. A valve 5? is interposed in the length of the pipe 55. The air sucked into the device, more particularly the vaporizing chamber, will pass through or along the wick and and into the mixing chamber, and out of the mixing chamber into the end l5 of the pipel5.

The mixing chamber is formed with a spirallyarranged plate Til defining a continuous spiral passage ll extending from the inlet 3'lA to the central outlet l6. Within the passage or passages are disposed flexible plates l2, preferably made of light sheet brass. The baffles normally close, or substantially close, the passage, but are flexed by the stream of fuel on its way to the intake manifold.

If the pipe 52 is not used, the wick unit, that is tubular member :33 with wick and form 44, may be easily removed for cleaning or replacement purposes, by first removing the lid L closing the top or" the casing C.

A jet (not shown) may be used in the tube l0, above the butterfly or control valve, to remove low grade residue and for idling the motor when the control valve is closed. This jet is attached to a suitable Dole pump, and may be also operated when starting the motor in cold weather.

In the modification shown in Figures 10 and 11 the upper part of the tube 43 is loosely packed with steel wool, or some other suitable type of metallic wool indicated at l. The metallic wool is preferably heated in any suitable way as by a heating jacket 2 which partly surrounds the upper part of the carburetor. The heating medium adapted to circulate through the jacket 2 may be re exhaust gases from the engine. Thus the pipe 3 (Fig. 11) connected with the exhaust manifold may conduct the exhaust gases to the jacket 2, and a pipe also connected with the jacket 2 may discharge the exhaust gases from the jacket. I have found that the metallic 'wool increases the efficiency of the engine, particularly when it is heated, due no doubt to the better mixing of the air and gasolene vapors caused by their passage through the mass of metallic wool, and to the in creased temperature imparted to the mixture (carbureted air) by the metallic wool. The metallic wool also functions to some extent as a filter.

The carbureted air, after leaving the mixing chamber 36 may pass through a second mass of metallic wool 5 in a suitable casing 6. The carbureted air enters this casing through a pipe 1 and leaves it through pipe 8. 9 preferably surrounds the casing B and may be connected to the exhaust manifold of the engine by a pipe 9 (Fig. 11) the gases being discharged from the jacket by a pipe 9". The function of the metallic wool in the casing 6 is similar to the function of the metallic wool in the upper part of the tube 43. It increases the temperature of the carbureted air and causes a more intimate mixture of the fuel vapor and air and thereby increases the efficiency of the engine. to some extent as a filter.

If desired, either of the two masses of metallic Wool may be omitted, only that shown at l in the tube 43, or that shown at 5 in the casing 6, being then employed.

The operation of the engine causes suction in the tube !5, in the mixing chamber, in the vaporizing chamber and in the tube 48, as a result of which air is sucked into the carburetor, first entering into the vaporizing chamber, then passing into and through the mixing chamber to be finally sucked into the intake manifold. The air passing up through the vaporizing chamber is caused to travel along and through the wick W, the bottom of which is immersed in gasolene enclosed in the bottom portion of the device or more particularly the vaporizing chamber. The carbureted air leaving the vaporizing chamber is sucked into the mixing chamber and from the mixing chamber into the pipe i5, and into the intake manifold. After the control or butterfly valve in the tube ID has been opened a certain amount, by operation of the rod if: from the accelerator control, the valve 26 is opened to admit air from the at- A heating jacket It also serves a mospliere into the mixing chamber to dilute the carbureted air.

In the modification of Figures 10 and 11 the mixture of fuel vapor and air, i. e., the carbureted air, passes through the heated mass of metallic wool thus raising the temperature of the mixture and efiecting a better mixing of the vapor and air. This may be accomplished in the upper portion of the vaporizing tube 55 before the carbureted air passes into the mixing chamber 36, or it may be accomplished in the casing 6 after the carbureted air leaves the mixing chamber 35, or it may be accomplished at both of these points as described above.

I claim:

1. In a carburetor for internal combustion engines, a casing adapted to contain a body of fuel, and having an air inlet and an outlet for the carbureted air, means for feeding fuel into said casing, means operatively connecting said outlet to the suction side of the engine, a tubular member in said casing between said inlet and outlet and extending to substantially the bottom wall of said casing, said tubular member having an aperture positioned to lie at least partly above the body of fuel to allow air sucked into said casing through said inlet to pass into said tubular member, and a wick in said tubular member disposed and formed to substantially extend between all four vertical walls of said tubular member and spanning the passage therethrough, said wick being adapted to be partly immersed in the body of fuel.

2. A carburetor in accordance withclaim 1 in which said wick is partly secured to said tubular member.

3. In a carburetor for internal combustion engines, a casing adapted to contain a body of fuel, an air inlet into said casing, an outlet from said casing for operative connection with the suction side of the engine, and a wick unit in said casing lying at least partially between said inlet and outlet comprising a tubular member adapted to extend to substantially the bottom wall of said casing, a centrally disposed member, and a wick secured to said members and disposed therebetween in zigzag formation.

4. A carburetor in accordance with claim 3 in which said centrally located member comprises a vertical wall and spaced rounded topand bottom plates partly embraced by said wick.

5. In a carburetor for internal combustion engines, a casing adapted to contain a body of fuel and having a removable lid closing the top, an inlet into said casing for admitting air thereinto, an outlet from said casing for operative connection with the suction side of the engine to suck the carbureted air out of said casing, and a wick unit in said casing adapted to be removably inserted into said casing from the top thereof comprising a tubular member adapted to rest upon the bottom Wall of said casing, a centrally disposed member and a wick secured to said members and disposed therebetween in zigzag formation.

6. A carburetor for internal combustion engines comprising a casing adapted to contain a body of fuel and having an air inlet and an outlet for the carbureted air, means for feeding fuel into said casing, means operatively connecting said outlet to the suction side of the engine, a tubular member in said casing between said inlet and outlet and extending to substantially the bottom wall of said casing, said tubular member having an aperture positioned to lie at least partly above the body of fuel to allow air sucked into said casing through said inlet to pass into said tubular member, a wick in said tubular member disposed and formed to substantially extend between all four vertical walls of said tubular member and adapted to be partly immersed in the body of fuel, a mass of metallic wool through which the carbureted air is adapted to pass, and means for heating the metallic wool.

7. A carburetor for internal combustion engines comprising a casing adapted to contain a body of fuel and having an air inlet and an outlet for the carbureted air, means for feeding fuel into said casing, means operatively connecting said outlet to the suction side of the engine, a tubular member in said casing between said inlet and outlet and extending to substantially the bottom wall of said casing, said tubular member having an aperture positioned to lie at least partly above the body of fuel to allow air sucked into said casing through said inlet to pass into said tubular member, a wick in said tubular member disposed and formed to substantially extend between all four vertical walls of said tubular member and adapted to be partly immersed in the body of fuel, and a mass of metallic wool in at least the upper portion of said tubular member through which the carbureted air is adapted to pass.

8. A carburetor in accordance with claim 7 in which means is provided for heating the metallic wool.

9. A carburetor for internal combustion engines comprising a casing adapted to contain a body of fuel and having an air inlet and an outlet for the carbureted air, means for feeding fuel into said casing, means operatively connecting said outlet to the suction side of the engine, a tubular member in said casing between said inlet and outlet and extending to substantially the bottom wall of said casing, said tubular member having an aperture positioned to lie at least partly above the body of fuel to allow air sucked into said casing through said inlet to pass into said tubular member, a wick in said tubular member disposed and formed to substantially extend between all four vertical walls of said tubular member and adapted to be partly immersed in the body of fuel, a casing through which the carbureted air is adapted to pass, a mass of metallic wool in said casing, and a heating jacket surrounding said casing.

10. In a carburetor for internal combustion engines, a casing adapted to contain a body of fuel and having an air inlet and an outlet for the carbureted air, means for feeding fuel into said casing, means operatively connecting said outlet to the suction side of the engine, a tubular member in said casing between said inlet and outlet and extending to substantially the bottom wall of said casing, said tubular member having an aperture positioned to lie at least partly above the body of fuel to allow air sucked into said casing through said inlet to pass into said tubular member, and a wick in said tubular member disposed and formed to substantially extend between all four vertical walls of said tubular member, said wick being adapted to be partly immersed in the body of fuel and said tubular member and wick being removable from said casing as a unit.

DUNCAN JAMES MACPHERSON. 

